How to Backup Joomla!
You can make a backup of your Joomla! web site in just a couple minutes, and that is well worth the effort to protect all the time you've invested in creating your site. I will give you step-by-step instructions for creating your own backups.Before we get into the details, you will need two bits of information:
First, you will need the top directory of your web site. This is the directory that contains the templates, plugins, and modules subdirectories (along with a bunch of other files and subdirs). In other words, you should include everything in that directory and its subdirectories.
Second, you will need the database connection settings. You can find these values in the configuration.php file.
With that information in hand, you can use How to Backup Your Hosted Site to make your backup.